WASHINGTON, April 1, 2009 – The leaders of the world’s two largest nuclear superpowers today agreed to start new talks aimed at reducing nuclear arms stockpiles, and to use the platform to “reset” relationships between the United States and Russia.

“What I believe we’ve begun today is a very constructive dialogue that will allow us to work on issues of mutual interest,” President Barack Obama said following his first meeting with Russian President Dmitriy Medvedev, held on the sidelines of the Group of 20 economic summit in London today.

Both presidents acknowledged a “drift” in relations between the United States and Russia, but said common interests should give them cause to work together.

In a joint statement released after the meeting, both leaders agreed “that the era when our countries viewed each other as enemies is long over,” and pledged a “substantive agenda for Russia and the United States to be developed over the coming months and years.”

“We … are ready to move beyond Cold War mentalities and chart a fresh start in relations between our two countries,” the statement reads.

In a separate news conference before the meeting, Obama said both countries have an interest in reducing nuclear stockpiles, reducing the threat of terrorism, and stabilizing the world economy. And, he said, nuclear arms talks are an ideal first front to begin moving the two countries toward common grounds.

“The presence of these deadly weapons, their proliferation, the possibility of them finding their way into the hands of terrorists, continues to be the gravest threat to humanity,” Obama said.

In the joint statement, Obama and Medvedev agreed to strengthen their obligations under Article VI of the treaty on nonproliferation of nuclear weapons and to replace the strategic arms reduction treaty. Talks on the new treaty are to begin immediately, and the two leaders called for a report on results by July.

Still, the two acknowledged that differences remain over missile defense assets in Europe.

The United States wants to base missile defense interceptors in Poland and associated radar in the Czech Republic. U.S. officials want to extend the zone of coverage in Europe for the potential long-range missile threat from Iran or others in the region.

Russian officials, however, have downplayed the threat from Iran and have been outspoken opponents of the plan. Both Defense Secretary Robert M. Gates and former Secretary of State Condoleezza Rice met with former Russian president Vladimir Putin and Medvedev in the past two years in Moscow for talks on the plan.

In the statement, though, the two leaders agreed to forge ahead on the missile defense discussions, and Medvedev later said he looks forward to meeting with Obama in Moscow in July.

“We discussed new possibilities for mutual international cooperation in the field of missile defense,” the statement reads. “The relationship between offensive and defensive arms will be discussed by the two governments.”

The statement also put Obama and Medvedev on the same side of the fight against al-Qaida and other insurgent groups operating in Afghanistan and Pakistan, and it expressed joint concern over a possible upcoming North Korean ballistic missile launch. The statement said the launch “would be damaging to peace and stability in the region.”